Winton H L, Bidwell J L, Armitage W J
Ophthalmology, School of Clinical Sciences, University of Bristol, Bristol Eye Hospital, Bristol, United Kingdom.
Cellular and Molecular Medicine, School of Medical Sciences, University of Bristol, Bristol, United Kingdom.
Transplant Proc. 2014 Jun;46(5):1540-7. doi: 10.1016/j.transproceed.2014.04.003.
The aim of this work was to investigate single-nucleotide polymorphisms (SNPs) in multiple genes on chromosome 6p in corneal transplant recipients known to be at increased risk of failure through immunologic rejection (ie, "high-risk" corneal transplants). Tumor necrosis factor alpha (TNF-α) is a key immunoregulatory cytokine in the ocular environment, interacting with a variety of factors in a synergistic way and playing a crucial role in many stages of the inflammatory response. Vascular endothelial growth factor (VEGF) is one of the most important angiogenic factors, supporting both hemangiogenesis and lymphangiogenesis, both key in transplant tolerance and rejection. Interleukin-17 (IL-17) is a multifunctional cytokine produced by T-helper 17 cells, exerting specific effector functions during an immune response. Association of SNPs in all 3 genes with corneal transplant outcome was therefore investigated.
Three hundred five corneal transplant recipients were followed for 3 years, and episodes of allograft rejection were recorded. With the use of patient DNA, 6 SNPs of 3 different genes on chromosome 6p were investigated. The TNF-α promoter SNP -308 G/A (rs1800629) was analyzed with the use of induced heteroduplex generation; 2 VEGF-A functional variants were analyzed, -2578 (rs699947) C/A and -1154 (rs1570360) G/A, with the use of Taqman genotyping assays; and 3 nonsynonymous IL-17F SNPs in exon 3 (negative strand), (rs2397084) A/G, (rs11465553) G/A, and (rs763780) A/G, were investigated with the use of direct sequencing. Haplotypes were inferred with the use of PHASE using positive strand alleles, and exact measures of association were determined with the use of Mid-P exact chi-square.
Six common haplotypes were inferred, with the haplotype TNF-α (rs1800629), VEGF-A (rs699947), (rs1570360), IL-17F (rs763780), (rs11465553), and (rs2397084) ACGTCT having a significant association with corneal transplant rejection (odds ratio, 1.78; 95% confidence interval, 1.01-3.11; P = .04).
The results suggest that patients carrying a combination of SNPs for TNF-α, VEGF-A, and IL-17F of ACGTCT haplotype may have an increased risk of corneal allograft rejection compared with patients carrying other haplotypes.
本研究旨在调查已知因免疫排斥而失败风险增加的角膜移植受者（即“高风险”角膜移植）6号染色体短臂上多个基因的单核苷酸多态性（SNP）。肿瘤坏死因子α（TNF-α）是眼内环境中的关键免疫调节细胞因子，以协同方式与多种因子相互作用，在炎症反应的许多阶段发挥关键作用。血管内皮生长因子（VEGF）是最重要的血管生成因子之一，支持血管生成和淋巴管生成，这两者在移植耐受和排斥中都起关键作用。白细胞介素-17（IL-17）是由辅助性T细胞17产生的多功能细胞因子，在免疫反应中发挥特定的效应功能。因此，研究了这3个基因中的SNP与角膜移植结果的相关性。
对305例角膜移植受者进行了3年的随访，并记录了同种异体移植排斥反应的发作情况。利用患者的DNA，研究了6号染色体短臂上3个不同基因的6个SNP。使用诱导异源双链体生成法分析TNF-α启动子SNP -308 G/A（rs1800629）；使用Taqman基因分型分析法分析2个VEGF-A功能变体，即-2578（rs699947）C/A和-1154（rs1570360）G/A；使用直接测序法研究外显子3（负链）中3个非同义IL-17F SNP，即（rs2397084）A/G、（rs11465553）G/A和（rs763780）A/G。使用PHASE利用正链等位基因推断单倍型，并使用Mid-P精确卡方检验确定确切的关联度。
推断出6种常见单倍型，其中单倍型TNF-α（rs1800629）、VEGF-A（rs699947）、（rs1570360）、IL-17F（rs763780）、（rs11465553）和（rs2397084）ACGTCT与角膜移植排斥反应有显著相关性（优势比，1.78；95%置信区间，1.01-3.11；P = 0.04）。
结果表明，与携带其他单倍型的患者相比，携带ACGTCT单倍型的TNF-α、VEGF-A和IL-17F SNP组合的患者角膜同种异体移植排斥反应的风险可能增加。
